Mannose-anchored quaternized chitosan/thiolated carboxymethyl chitosan composite NPs as mucoadhesive carrier for drug delivery.

There are various challenges for the mucosal delivery of drug, which is largely attributed to the absence of effective drug carriers that can make delivery to mucosal sites. In the present study, we aimed to synthesize bifunctional mucoadhesive nanoparticles (NPs) that could be used for mucosal delivery. N-2-Hydroxypropyl trimethyl ammonium chloride chitosan (M-N-2-HACC) was modified with D-mannose, and N-acetyl-L-cysteine (NAC) was immobilized on the carboxymethyl chitosan (N-CMCS). The electrostatic interaction between the two substances was used to produce mannose-modified thiolated chitosan NPs (M-N-2-HACC/N-CMCS NPs). The NPs showed a particle size of 196.72 ± 0.45 nm and zeta potential of 17.12 ± 0.50 mV. Moreover, it demonstrated high hydrophilicity, enduring drug release, stability, safety, and mucosal adhesion, which contributed to the effectiveness of mucosal administration. Additionally, the NPs could be instantly absorbed by macrophages. Collectively, these results suggested that M-N-2-HACC/N-CMCS NPs could be used as a promising candidate for mucosal delivery.

Development of novel mucoadhesive gels containing nanoparticle for buccal administration of dexamethasone

Abstract This study aimed to develop promising and innovative mucoadhesive gel systems containing dexamethasone-loaded nanoparticle to increase the effectiveness of treatment for oral precancerous lesions and to reduce side effects. In this respect, a dexamethasone-loaded nanoparticle formulation was prepared by using emulsification/solvent evaporation method. The nanoparticle has high zeta potential (-10.3±0.5 mV), low particle size (218.42±2.1), low polydispersity index (0.070±0.014) and high encapsulation efficiency (95.018±2.982%). To improve the mucosal retention time, the dexamethasone-loaded nanoparticle was dispersed in mucoadhesive gel using gellan gum. The developed gels offered appropriate pH value, high drug content, suitable mechanical and mucoadhesive performance and appropriate viscosity for mucosal administration. All formulations exhibited plastic flow and typical gel-type mechanical spectra after the determined frequency value. The developed formulations exhibited extended drug release as intended for these systems. Cytotoxicity was tested by MTT assay in human epithelioid carcinoma cell (HeLa) in vitro. The MTT assay showed that the blank formulations were non-toxic to cells. It was observed that the bioactivity of the free dexamethasone was potentiated by mucoadhesive gels containing dexamethasone-loaded nanoparticle in HeLa cells. Results from this study indicate that mucoadhesive gels are effective for the local treatment of precancerous lesions. Our findings showed that the developed formulations were worthy of further studies.

Nanotechnologies for the delivery of biologicals: Historical perspective and current landscape.

Biological macromolecule-based therapeutics irrupted in the pharmaceutical scene generating a great hope due to their outstanding specificity and potency. However, given their susceptibility to degradation and limited capacity to overcome biological barriers new delivery technologies had to be developed for them to reach their targets. This review aims at analyzing the historical seminal advances that shaped the development of the protein/peptide delivery field, along with the emerging technologies on the lead of the current landscape. Particularly, focus is made on technologies with a potential for transmucosal systemic delivery of protein/peptide drugs, followed by approaches for the delivery of antigens as new vaccination strategies, and formulations of biological drugs in oncology, with special emphasis on mAbs. Finally, a discussion of the key challenges the field is facing, along with an overview of prospective advances are provided.

Size shifting of solid lipid nanoparticle system triggered by alkaline phosphatase for site specific mucosal drug delivery.

We aim to prepare a size-shifting nanocarrier for site-targeting mucosal drug delivery that can penetrate through mucus gel layer and remain close to the absorption membrane. As nanocarriers can be engineered to penetrate mucus but they can also back diffuse into outer mucus regions, a size shifting to micron range once they have reached the absorption membrane would prevent back-diffusion effect and extend drug release over a long period of time. For this purpose, we loaded solid lipid nanoparticles (SLN) with a phosphate ester surfactant and octadecylamine. Alkaline phosphatase (AP), a membrane bound enzyme was for the first time utilized as an in situ partner for triggering the size conversion at epithelial cell surface. Having the size of ~120 nm, SLN with hydrophilic and phosphate-decorated shells were shown to penetrate through mucus gel and form aggregates above cell layer surface. Aggregates of 5-8 µm were formed due to interparticle interactions induced by enzymatic phosphate removal after ~30 min in contact with isolated AP. The developed SLN system could be a potential tool for mucosal drug delivery to AP-expressing tissues like colon, lung, cervix, vagina and some mucus-secreting tumors.

Mucosal Delivery of Recombinant Vesicular Stomatitis Virus Vectors Expressing Envelope Proteins of Respiratory Syncytial Virus Induces Protective Immunity in Cotton Rats.

Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract (LRT) infections, with increased severity in high-risk human populations, such as infants, the immunocompromised, and the elderly. Although the virus was identified more than 60 years ago, there is still no licensed vaccine available. Over the years, several vaccine delivery strategies have been evaluated. In this study, we developed two recombinant vesicular stomatitis virus (rVSV) vector-based vaccine candidates expressing the RSV-G (attachment) protein (rVSV-G) or F (fusion) protein (rVSV-F). All vectors were evaluated in the cotton rat animal model for their in vivo immunogenicity and protective efficacy against an RSV-A2 virus challenge. Intranasal (i.n.) delivery of rVSV-G and rVSV-F together completely protected the lower respiratory tract (lungs) at doses as low as 103 PFU. In contrast, doses greater than 106 PFU were required to protect the upper respiratory tract (URT) completely. Reimmunization of RSV-immune cotton rats was most effective with rVSV-F. In immunized animals, overall antibody responses were sufficient for protection, whereas CD4 and CD8 T cells were not necessary. A prime-boost immunization regimen increased both protection and neutralizing antibody titers. Overall, mucosally delivered rVSV-vector-based RSV vaccine candidates induce protective immunity and therefore represent a promising immunization regimen against RSV infection.IMPORTANCE Even after decades of intensive research efforts, a safe and efficacious RSV vaccine remains elusive. Expression of heterologous antigens from rVSV vectors has demonstrated several practical and safety advantages over other virus vector systems and live attenuated vaccines. In this study, we developed safe and efficacious vaccine candidates by expressing the two major immunogenic RSV surface proteins in rVSV vectors and delivering them mucosally in a prime-boost regimen. The main immune parameter responsible for protection was the antibody response. These vaccine candidates induced complete protection of both the upper and lower respiratory tracts.

Transmucosal drug administration as an alternative route in palliative and end-of-life care during the COVID-19 pandemic.

The Coronavirus disease 2019 (COVID-19) pandemic has led to a surge in need for alternative routes of administration of drugs for end of life and palliative care, particularly in community settings. Transmucosal routes include intranasal, buccal, sublingual and rectal. They are non-invasive routes for systemic drug delivery with the possibility of self-administration, or administration by family caregivers. In addition, their ability to offer rapid onset of action with reduced first-pass metabolism make them suitable for use in palliative and end-of-life care to provide fast relief of symptoms. This is particularly important in COVID-19, as patients can deteriorate rapidly. Despite the advantages, these routes of administration face challenges including a relatively small surface area for effective drug absorption, small volume of fluid for drug dissolution and the presence of a mucus barrier, thereby limiting the number of drugs that are suitable to be delivered through the transmucosal route. In this review, the merits, challenges and limitations of each of these transmucosal routes are discussed. The goals are to provide insights into using transmucosal drug delivery to bring about the best possible symptom management for patients at the end of life, and to inspire scientists to develop new delivery systems to provide effective symptom management for this group of patients.

Innate immune memory of tissue-resident macrophages and trained innate immunity: Re-vamping vaccine concept and strategies.

In the past few years, our understanding of immunological memory has evolved remarkably due to a growing body of new knowledge in innate immune memory and immunity. Immunological memory now encompasses both innate and adaptive immune memory. The hypo-reactive and hyper-reactive types of innate immune memory lead to a suppressed and enhanced innate immune protective outcome, respectively. The latter is also named trained innate immunity (TII). The emerging information on innate immune memory has not only shed new light on the mechanisms of host defense but is also revolutionizing our long-held view of vaccination and vaccine strategies. Our current review will examine recent progress and knowledge gaps in innate immune memory with a focus on tissue-resident Mϕs, particularly lung Mϕs, and their relationship to local antimicrobial innate immunity. We will also discuss the impact of innate immune memory and TII on our understanding of vaccine concept and strategies and the significance of respiratory mucosal route of vaccination against respiratory pathogens.

Local immune and microbiological responses to mucosal administration of a Liposome-TLR agonist immunotherapeutic in dogs.

BACKGROUND: Non-specific immunotherapeutics have been evaluated previously in dogs, primarily for cancer treatment. However, there remains a need for a more broadly targeted, general purpose immunotherapeutic capable of activating innate immune defenses for non-specific protection or early treatment of viral and bacterial infections. To address need, our group has developed a liposomal immune stimulant (liposome-TLR complexes, LTC) containing TLR 3 and 9 agonists specifically designed to activate mucosal immune defenses in sites such as nasal cavity and oropharynx, following topical delivery. In this study, we evaluated the local immune stimulatory properties of LTC in vitro and in healthy purpose-bred dogs, including activation of cellular recruitment and cytokine production. The ability of LTC treatment to elicit effective antiviral immunity was assessed in dogs following a canine herpesvirus outbreak, and the impact of LTC treatment on the local microbiome of the oropharynx was also investigated. RESULTS: These studies revealed that LTC potently activated innate immune responses in vitro and triggered significant recruitment of inflammatory monocytes and T cells into the nasal cavity and oropharynx of healthy dogs. Administration of LTC to dogs shortly after an outbreak of canine herpesvirus infection resulted in significant reduction in clinical signs of infection. Interestingly, administration of LTC to healthy dogs did not disrupt the microbiome in the oropharynx, suggesting resiliency of the microflora to transient immune activation. CONCLUSIONS: Taken together, these results indicate that LTC administration mucosally to dogs can trigger local innate immune activation and activation of antiviral immunity, without significantly disrupting the composition of the local microbiome. Thus, the LTC immune stimulant has potential for use as a non-specific immunotherapy for prevention or early treatment of viral and bacterial infections in dogs.

Intranasal drug delivery devices are a potential contamination source of airways / Dispositivos intranasais de medicamentos são uma potencial fonte de contaminação das vias aéreas

Background: The use of intranasal drug delivery devices (IDDD) for the treatment of allergic rhinitis (AR) is frequent because they are simple, efficient, and safe, and mainly because they are perceived as low-risk. However, it is speculated that contact between the nasal mucosa and an IDDD may give rise to infections once the nose is colonized by bacteria, and there are currently no proper instructions for IDDD sanitization. The objective of this study was to evaluate the possibility of contamination of an IDDD for topical medication after simulating use in healthy individuals. Methods: The in vitro study consisted of 14 healthy individuals of both sexes, between the ages of 18 and 24 years. Samples were collected immediately after the opening of each IDDD and after simulating use by the subjects. Afterwards, the samples were deposited in tubes and kept in an incubator at 37 °C. After 48 hours, the samples were inoculated on Müller-Hinton agar. Qualitative analyses of the appearance of the samples were performed after 24 and 48 hours, and after 72 hours the presence or absence of bacteria was evaluated macroscopically. Results: After 24 hours of incubation, 21.4% (n = 3) of the samples presented with a turbid appearance and after 48h, 71% (n = 10) of the samples presented with a turbid appearance and positive bacterial growth. Conclusion: The results suggest that IDDDs for topical medications may be important sources of contamination or recontamination of the nasal mucosa of individuals who are being treated for upper respiratory tract conditions. A better understanding of the risks of re-using IDDDs after previous contact with the nasal mucosa will improve guidelines on hygiene procedures and prevention of related risks.

Introdução: O uso de dispositivos intranasais para administração de medicamentos (IDDD) no tratamento da rinite alérgica (AR) é frequente, por serem simples, eficientes e seguros, e principalmente por serem de baixo risco. No entanto, especula-se que o contato entre a mucosa nasal e um IDDD possa causar infecções, uma vez que o nariz é colonizado por bactérias, e atualmente não há instruções adequadas para a higienização do IDDD. O objetivo deste estudo foi avaliar a possibilidade de contaminação de um IDDD para medicação tópica após simulação de uso em indivíduos saudáveis. Métodos: O estudo in vitro foi composto por 14 indivíduos saudáveis, de ambos os sexos, com idades entre 18 e 24 anos. As amostras foram coletadas imediatamente após a abertura de cada IDDD, e após a simulação do uso pelos sujeitos. Posteriormente, as amostras foram depositadas em tubos e mantidas em incubadora a 37 °C. Após 48 horas, as amostras foram inoculadas em ágar Müller-Hinton. As análises qualitativas da aparência das amostras foram realizadas após 24 e 48 horas, e após 72 horas a presença ou ausência de bactérias foi avaliada macroscopicamente. Resultados: Após 24 horas de incubação, 21,4% (n = 3) das amostras apresentaram aparência turva e, após 48h, 71% (n = 10) das amostras apresentaram aparência turva e crescimento bacteriano positivo. Conclusão: Os resultados sugerem que IDDDs para medicações tópicas podem ser importantes fontes de contaminação ou recontaminação da mucosa nasal de indivíduos em tratamento para condições do trato respiratório superior. Uma melhor compreensão dos riscos da reutilização de IDDDs após contato prévio com a mucosa nasal, melhorará as diretrizes sobre procedimentos de higiene e prevenção de riscos relacionados.

Efficacy and Safety of the Local Application of Mitomycin C to Recurrent Esophageal Strictures in Children.

OBJECTIVES: Research on long-term use of mitomycin C (MC) for recurrent esophageal stenoses is limited. We assessed the long-term efficacy and safety of local application of MC for recurrent esophageal stenoses in children. METHODS: This was a retrospective study of 39 patients (17 girls) with a median age of 19.5 months (range: 2.4-196.0) at the time of MC application. The etiologies of stenosis were esophageal atresia (n = 25), caustic ingestion (n = 9), congenital esophageal stenosis (n = 3), and other causes (n = 2). Stenosis was single in 35 (90%) patients and multiple in 4 (10%). Before MC, patients underwent multiple repeated dilations (median: 3 dilations per child [range: 2-26]) over a median period of 7 months (range: 2.6-49.3). Treatment success was defined a priori as a reduction in the number of dilations over the same period from before to after the application of MC. RESULTS: For 26 (67%) patients, the application of MC was considered a success: 102 versus 17 dilatations (P < 0.0001). Sixteen (41%) patients never required additional dilation during the follow-up after MC application (median: 3.1 years [range: 0.6-8.5]). No complication related to MC was observed. Biopsies at the site of MC application were performed at maximal follow-up in 16 patients and revealed no dysplasia. Three factors were associated with success of MC: single stenosis, short stenosis, and esophageal atresia type III. CONCLUSIONS: This study is the largest series reported showing that topical application of MC is an efficient and safe treatment for recurrent esophageal stenosis in children.

Expert consensus on the management of breakthrough cancer pain in older patients. A Delphi study.

OBJECTIVES: We aimed to generate expert-based recommendations on the management of breakthrough cancer pain (BTcP) in older patients with cancer. MATERIAL AND METHODS: A two-round multidisciplinary Delphi study. Specialists rated their agreement with a set of statements using a nine-point Likert scale (one = totally disagree and nine = totally agree). Statements were classified as appropriate (median ranged from seven to nine), irrelevant (median ranged from four to six) or inappropriate (median ranged from one to three). Consensus was established when at least two thirds of the panel scored within any of the ranges. RESULTS: A total of 64 specialists from pain units (44.4%), palliative care units (25.4%), medical oncology (19.1%), geriatric medicine (7.9%) and others (3.2%), participated in two consultation rounds. Specialists agreed that effective coordination between the different specialties and levels of care is essential for proper management of BTcP. Most participants (81.3%) supported the assessment of frailty and resolved (96.8%) that frailty status is a better indicator of patient needs than biological age. Participants agreed (75.8%) in the application of the Davies algorithm for diagnosis of BTcP in older patients. A strong consensus was achieved regarding which pharmacological treatment (transmucosal fentanyl) and dosing method (start low and go slow) are the most suitable for the older population. No agreement was reached on how interventionist techniques should be integrated into the therapeutic strategy for BTcP. CONCLUSIONS: The present Delphi has generated a set of recommendations that will help healthcare professionals in the management of BTcP in older patients.

Association of a Risk Evaluation and Mitigation Strategy Program With Transmucosal Fentanyl Prescribing.

Importance: Transmucosal immediate-release fentanyl (TIRF) drugs are potent, rapid-acting opioids approved to treat breakthrough pain in patients with cancer who are tolerant to other around-the-clock opioid analgesics. In March 2012, a US Food and Drug Administration-approved Risk Evaluation and Mitigation Strategy (REMS) was implemented, mandating prescribers, distributors, pharmacies, and patients to enroll in the REMS to prescribe, dispense, or receive TIRF drugs. Objective: To evaluate the association of the TIRF-REMS Access Program with TIRF prescribing. Design, Setting, and Participants: Cohort study using an interrupted time series analysis of TIRF prescriptions to Medicare Part D beneficiaries nationwide from 2010 to 2014. Data were analyzed from August 2017 through July 2018. Main Outcomes and Measures: Prescribing of TIRF per 100 000 Medicare Part D beneficiaries, overall and stratified by cancer status; percentage of TIRF prescriptions for patients without cancer, overall and by brand; and percentage of TIRF prescriptions for patients without known opioid tolerance, defined as patients prescribed at least 60 morphine milligram equivalents per day, overall and by brand. Results: There were 99 601 TIRF prescriptions written by 8619 clinicians to 10 472 patients. Most of the patients (79%) were younger than 65 years (mean [SD] age, 56 [13] years), and most (67%) did not have cancer. Implementation of TIRF-REMS was associated with a 26.7% relative level decrease in TIRF prescribing (95% CI, -33.3% to -19.4%; P < .001) but was followed by 2.0% monthly increases in prescribing (95% CI, 1.3% to 2.7%; P < .001). Sensitivity analyses that accounted for overall opioid prescribing trends were consistent with these findings. Furthermore, there were no significant changes associated with REMS implementation in the level (0.47%; 95% CI, -5.36% to 4.69%; P = .85) or trend (0.16%; 95% CI, -0.06% to 0.37%; P = .15) of the percentage of prescriptions for patients without cancer. However, a sensitivity analysis that used a broader cancer definition found implementation was associated with a 7.2% (95% CI, -13.5% to -0.48%; P = .04) level decrease in the percentage of TIRF prescriptions for patients without cancer. Lastly, the TIRF-REMS was associated with a 22.5% level decline in the percentage of TIRF prescriptions for patients without known opioid tolerance (95% CI, -36.1% to -5.95%; P = .01) followed by 1.98% monthly decreases (95% CI, -3.19% to -0.80%; P = .001). Conclusions and Relevance: Implementation of the TIRF-REMS Access Program, a restrictive drug distribution program, was associated with a temporary reduction in the rate of TIRF prescribing to Medicare Part D beneficiaries, and with a sustained decrease in the percentage of TIRF prescriptions for patients without known opioid tolerance. Implementation may have also been associated with a temporary decrease in the percentage of TIRF prescriptions for patients without cancer.

Assessment of the FDA Risk Evaluation and Mitigation Strategy for Transmucosal Immediate-Release Fentanyl Products.

IMPORTANCE: Transmucosal immediate-release fentanyls (TIRFs), indicated solely for breakthrough cancer pain in opioid-tolerant patients, are subject to a US Food and Drug Administration (FDA) Risk Evaluation and Mitigation Strategy (REMS) to prevent them from being prescribed inappropriately. OBJECTIVES: To evaluate knowledge assessments of pharmacists, prescribers, and patients regarding appropriate TIRF use; to describe sponsor assessments, based on claims data, of whether the REMS program was meeting its goals; and to characterize how the FDA responded to REMS assessments. DESIGN, SETTING, AND PARTICIPANTS: Qualitative analysis of 4877 pages of FDA documents obtained through a Freedom of Information Act request, including 6 annual REMS assessment reports (2012-2017), FDA evaluations of these reports, and FDA-sponsor correspondence about safety issues. EXPOSURE: A REMS program to reduce the risk of adverse outcomes, including misuse, abuse, addiction, and overdose, arising from use of TIRFs. MAIN OUTCOMES AND MEASURES: (1) Knowledge assessments of pharmacists, prescribers, and patients; (2) survey and claims-based prescribing assessments; (3) FDA and TIRF sponsor communications; (4) modifications to the REMS program; and (5) disenrollment of noncompliant prescribers. RESULTS: Twelve months after initiation of the program, 24 of 302 pharmacists (7.9%), 35 of 302 prescribers (11.6%), and 5 of 192 patients (2.6%) incorrectly reported that TIRFs can be prescribed to opioid-nontolerant patients, with similar levels of misunderstanding maintained in the subsequent reports. At 60 months, product-specific analyses of claims data indicated that between 34.6% and 55.4% of patients prescribed TIRFs were opioid-nontolerant. In the 48-month survey, 106 of 310 prescribers (34.2%) reported prescribing TIRFs for opioid-tolerant patients with chronic, noncancer pain; at 60 months, 54 of 302 prescribers (18.4%) and 148 of 310 patients (47.7%) erroneously reported that TIRFs were FDA-approved for such use. Over the 60-month period examined, there were few substantive changes made to the REMS to address evidence of high rates of off-label TIRF use, and, although the REMS program had a noncompliance plan, there was no report of prescribers being disenrolled for inappropriate prescribing. CONCLUSIONS AND RELEVANCE: In this review of FDA documents pertaining to the TIRF REMS, surveys of pharmacists, prescribers, and patients reflected generally high levels of knowledge regarding proper TIRF prescribing, yet some survey items as well as claims-based analyses indicated substantial rates of inappropriate TIRF use. Despite these findings, the FDA did not require substantive changes to the program.

Oxidized Carbon Nanosphere-Based Subunit Vaccine Delivery System Elicited Robust Th1 and Cytotoxic T Cell Responses.

Subunit vaccines are safer and more stable than live vaccines although they have the disadvantage of eliciting poor immune response. To develop a subunit vaccine, an effective delivery system targeting the key elements of the protective immune response is a prerequisite. In this study, oxidized carbon nanospheres (OCNs) were used as a subunit vaccine delivery system and tuberculosis (TB) was chosen as a model disease. TB is among the deadliest infectious diseases worldwide and an effective vaccine is urgently needed. The ability of OCNs to deliver recombinant Mycobacterium tuberculosis (Mtb) proteins, Ag85B and HspX, into bone marrow derived macrophages (BMDMs) and dendritic cells (BMDCs) was investigated. For immunization, OCNs were mixed with the two TB antigens as well as the adjuvant monophosphoryl lipid A (MPL). The protective efficacy was analyzed in vaccinated mice by aerosol Mtb challenge with a virulent strain of Mtb and the bacterial burdens were measured. The results showed that OCNs are highly effective in delivering Mtb proteins into the cytosol of BMDMs and BMDCs. Upon immunization, this vaccine formula induced robust Th1 immune response characterized by cytokine profiles from restimulated splenocytes and specific antibody titer. More importantly, enhanced cytotoxic CD8⁺ T cell activation was observed. However, it did not reduce the bacteria burden in the lung and spleen from the aerosol Mtb challenge. Taken together, OCNs are highly effective in delivering subunit protein vaccine and induce robust Th1 and CD8⁺ T cell response. This vaccine delivery system is suitable for application in settings where cell-mediated immune response is needed.

Epithelial boost enhances antigen expression by vaccinia virus for the generation of potent CD8+ T cell-mediated antitumor immunity following DNA priming vaccination.

While both pNGVL4a-Sig/E7(detox)/HSP70 DNA vaccine and TA-HPV recombinant vaccinia viral vector-based vaccines have elicited HPV-specific CD8+ T cell responses in HPV16/E7-expressing tumor models, and been used as prime-boost regimen to enhance HPV-specific immune responses in humans (NCT00788164), the optimal route of administration for TA-HPV remains unclear. In a preclinical model, we examined the immunogenicity of priming with intramuscular pNGVL4a-Sig/E7(detox)/HSP70 followed by TA-HPV boost through different administration routes. We observed that priming twice with a pNGVL4a-Sig/E7(detox)/HSP70 followed by a single TA-HPV immunization boost through skin scarification generated the strongest antigen-specific CD8+ T cell response in C57BL/6 mice. These data translate to tumor control and prolonged survival of treated mice. Our results provide rationale for future clinical testing of intramuscular pNGVL4a-Sig/E7(detox)/HSP70 DNA vaccine prime, TA-HPV vaccine skin scarification boost immunization regimen for the control of HPV-associated diseases.

Toxicity of silver ions, metallic silver, and silver nanoparticle materials after in vivo dermal and mucosal surface exposure: A review.

Silver is used in different applications that result in contact with skin and mucosal surfaces (e.g., jewelry, wound dressings, or eye drops). Intact skin poses an effective barrier against the absorption of silver. Mucosal surfaces are observed to be less effective barriers and compromised skin is often a poor barrier. Silver can deposit as particles in the human body causing a blue-gray discoloration known as argyria. Urine and feces are reported pathways of excretion. Acute human mortality has been observed following an abortion procedure involving the intrauterine administration of 7 g silver nitrate (64 mg silver/kg body weight). Localized argyria has been reported with exposure to silver ions, metallic surfaces, and nanocrystalline silver. Generalized argyria was observed with ionic and nanocrystalline silver in humans at cumulative doses in the range of 70-1500 mg silver/kg body weight. Silver is observed to have a low potential for skin irritation. Eye irritation and some cases of allergic contact dermatitis have been reported. Silver may cause genotoxicity, but additional data are required to assess its carcinogenic potential. Other reported toxicities include hepatic, renal, neurological, and hematological effects.

Breakthrough cancer pain (BTcP) management: a review of international and national guidelines.

OBJECTIVE: Breakthrough cancer pain (BTcP) is common and has a significant impact on the quality of life of patients with cancer. This review compares current national/international BTcP guidelines in order to identify disparities and priorities for further research. METHODS: Relevant guidelines were identified using searches of PubMed, the National Guideline Clearinghouse, the internet (commercial search engines), and correspondence with key opinion leaders and relevant pharmaceutical companies. Identified guidelines were compared, using the Association for Palliative Medicine of Great Britain and Ireland recommendations as the 'reference' guideline. RESULTS: Ten specific BTcP guidelines were identified/reviewed, as well as major international generic cancer pain guidelines. In general, there was good agreement between the specific BTcP guidelines, although there remain some differences in terms of definition, diagnostic criteria and treatment of BTcP. Disparities between the different BTcP guidelines invariably reflect personal opinion rather than research evidence. Generic cancer pain guidelines continue to support the use of oral opioids as rescue medication, while specific BTcP guidelines invariably endorse the use of transmucosal opioids as rescue medication. CONCLUSION: Current guidelines agree on many aspects of the management of BTcP. However, the evidence to support current guidelines remains low grade, and so more research is needed in this area of care. Moreover, there needs to be an international consensus on the definition and diagnosis criteria of BTcP.

Efficacy of injecting platelet concentrate combined with hyaluronic acid for the treatment of vulvovaginal atrophy in postmenopausal women with history of breast cancer: a phase 2 pilot study.

OBJECTIVE: Approximately 50% to 70% of breast cancer survivors are affected by one or more symptoms of vulvovaginal atrophy (VVA). For those who cannot take hormone therapy, autologous platelet-rich plasma combined with hyaluronic acid (A-PRP-HA) may provide a new alternative therapy for the treatment of VVA in postmenopausal women with history of breast cancer. METHODS: We enrolled 20 postmenopausal breast cancers survivors with VVA and a score of <15 on the Gloria Bachman Vaginal Health Index (VHI) comprised of five items including: vaginal pH, elasticity, fluid volume (secretions), epithelial integrity, and moisture.We administered intramucosal injections of A-PRP combined with HA (Regenkit) and performed clinical evaluations at 0, 1, 3, and 6 months. Primary endpoint: evaluation of vulvovaginal mucosa changes using the VHI; secondary endpoint: evaluation of dyspareunia and sexual dysfunction based on the Female Sexual Distress (FSD) score. RESULTS: All participants (20 women) showed improvement in the clinical symptoms of vaginal dryness and dyspareunia. The VHI score showed a significant increase at 6 months, going from a total baseline score (pretreatment) of 10.7 ±â€Š2.12 to 20.75 ±â€Š4.8 (P < 0.0001) at 6 months. Improvement in hydration and vaginal epithelial integrity was reported. A VHI score of > 15 showed a successful treatment outcome. The FSD score decreased significantly during the study, from a baseline score of 36.35 ±â€Š2.53 pretreatment to 30.15 ±â€Š2.47 6 months after treatment, representing improvement of 17% (P < 0.0001, respectively). No adverse events were reported. CONCLUSIONS: The injection of A-PRP-HA appeared to be a promising method to improve the trophicity and hydration of vaginal mucosa for the treatment of VVA in postmenopausal breast cancer survivors with contraindications to hormone therapy.